Winter Storm Stella unleashed its fury on much of the northeastern United States on March 14 dropping snow and sleet across the region and leading to school closures and thousands of flight cancellations (AFP Photo/DON EMMERT)

Winter Storm Stella lashed the northeastern United States with sleet and snow Tuesday, cancelling thousands of flights, closing schools and shutting stores, but New York and Washington escaped the worst of the weather.

Blizzard warnings were issued in parts of Connecticut, Massachusetts and upstate New York, but were lifted for New York City, the US financial capital home to 8.4 million residents, where snow turned to sleet and hail.

Dire forecasts forced the postponement of the first meeting between US President Donald Trump and German Chancellor Angela Merkel in Washington until Friday, but in the end, snowfall in the US capital was light.

The National Weather Service (NWS) drastically revised down New York City's expected accumulation with 7.2 inches (18 centimeters) recorded in Central Park, and 10-13 inches in parts of neighboring New Jersey and Connecticut.

Instead the trajectory of the storm shifted west and north, bringing up to 30 inches to central parts of New York state with strong winds causing whiteout conditions, and heavy snow further north.

"The storm is not delivering as much snow as forecasted at all and that is very good for the people of New York City, but the conditions are still very dangerous," Mayor Bill de Blasio told reporters.

He urged people to stay indoors as much as possible, warning that snow, sleet and freezing rain would continue throughout the afternoon combined with wind gusts as high as 50 miles per hour (80 kilometers per hour).

Temperatures would dip below freezing overnight, making roads and sidewalks treacherous, and a city-wide state of emergency would remain in place until midnight (0400 GMT Wednesday), he said.

While the New York subway and bus services were operating, much of the city remained quiet with schools, shops and businesses largely closed as workers shovelled snow.

New York's John F. Kennedy and LaGuardia airports and Newark Liberty International Airport were largely shut, with the majority of flights cancelled, and trains heading north towards Boston were also suspended.

Autumn Young, 35, the owner of a soap company, said she had been stranded at Grand Central Station since 6:00 am after her flight to see family in North Carolina and her train home were cancelled.

"I can't even get out of the city. I've missed a whole day of work and meetings," Young told AFP.

"It sucks, it's awful. I am traveling with my service dog -- he can't go on the sidewalk because the salt is bad for his feet."

The United Nations headquarters closed for the day, as did the courts and a string of popular museums, some of the most-visited tourist attractions in the city.

Officials announced that schools and rail services would re-open Wednesday.

More than 8,700 flights were canceled Monday through Wednesday, with airports in New York, Boston, Baltimore, Washington and Philadelphia hit hardest, according to the tracking service FlightAware.

US ambassador to the United Nations, Nikki Haley, tweeted a picture of the snow saying, "A great day to binge watch 'The Americans'" -- a reference to the thriller TV series about Russian spies embedded in US suburbia.

Her post triggered a stream of mockery, in light of the controversy over Russian meddling in last year's election that has dogged Trump's presidency.

"Mother Nature is an unpredictable lady sometimes," said New York State Governor Andrew Cuomo after meteorologists conceded it was no longer going to be the worst East Coast storm in an unusually mild winter.

"It has been less snowfall than we predicted, less disruption," Cuomo said.

Neither was there major damage in neighboring New Jersey.

"The storm has under-performed," said the state's Republican Governor Chris Christie.

In 2016, a record 27.3 inches fell in Central Park in 24 hours in a storm dubbed "Snowzilla" that paralyzed parts of the northeast and left 18 people dead.

The NWS said winter storm warnings were in effect from Maine down to eastern West Virginia, but snowfall further south was minimal.

A few inches of snow, sleet and ice covered the streets in the Washington area, where federal workers were allowed to arrive three hours late and the capital's subway system operated on a weekend schedule.